Problem 373

Summary: incorrect nucleon counting and momentum checking in G4ReactionDynamics
Product: Geant4 Reporter: dennis.herbert.wright
Component: processes/hadronicAssignee: Hans-Peter.Wellisch
Status: CLOSED FIXED    
Severity: normal    
Priority: P3    
Version: 4.0   
Hardware: All   
OS: All   

Description dennis.herbert.wright 2002-05-17 17:00:13 CEST 
In G4ReactionDynamics::GenerateXandPt the nucleon counting is incorrect.  When
adding particles from the intranuclear cascade, the neutrons and protons need
to accounted for separately.  This also applies to the AddBlackTrackParticles
method where only the nucleon mass is considered but not the charge of the
nucleon.

Also in GenerateXandPt the method MomentumCheck (at the end of GenerateXandPt)
should not be used.  This method prohibits an outgoing particle from having more
momentum than it had originally.  However, this case is physically possible and
its removal cuts off the edges of some distributions.
Comment 1 Hans-Peter.Wellisch 2002-06-04 04:18:59 CEST 
see  bug 374 for applicable comments.
Comment 2 Hans-Peter.Wellisch 2002-11-08 09:04:59 CET 
nucleons are now accounted for correctly, and the MomentumCheck was indeed a
fudge. They are not accounted for separately, though, for the time being, as the
determination of the black-track particle algorithm for the time being
introduces a still larger error. It stays on the list, to be done once BTP is
dealt with.

Thank you for reporting this.

Many greetings,

Hans-Peter.